5

[7] A pentagram, or five-pointed polygram, is a star polygon constructed by connecting some non-adjacent of a regular pentagon as self-intersecting edges.

[8] The internal geometry of the pentagon and pentagram (represented by its Schläfli symbol {5/2}) appears prominently in Penrose tilings.

There are five regular Platonic solids the tetrahedron, the cube, the octahedron, the dodecahedron, and the icosahedron.

[10] Five is a lower depending for the chromatic number of the plane, but this may depend on the choice of set-theoretical axioms:[11] The plane contains a total of five Bravais lattices, or arrays of points defined by discrete translation operations.

Uniform tilings of the plane, are generated from combinations of only five regular polygons.

[18]Every odd number greater than five is conjectured to be expressible as the sum of three prime numbers; Helfgott has provided a proof of this[19] (also known as the odd Goldbach conjecture) that is already widely acknowledged by mathematicians as it still undergoes peer-review.

[22]: p.54  A centralizer of an element of order 5 inside the largest sporadic group

The Kushana and Gupta empires in what is now India had among themselves several forms that bear no resemblance to the modern digit.

[25] It was from those digits that Europeans finally came up with the modern 5 (represented in writings by Dürer, for example).

On the seven-segment display of a calculator and digital clock, it is often represented by five segments at four successive turns from top to bottom, rotating counterclockwise first, then clockwise, and vice versa.

[citation needed] The pentagram, or five-pointed star, bears mystic significance in various belief systems including Baháʼí, Christianity, Freemasonry, Satanism, Taoism, Thelema, and Wicca.

The four-dimensional 5-cell is the simplest regular polychoron .
The smallest non-trivial magic square
This diagram shows the subquotient relations of the twenty-six sporadic groups ; the five Mathieu groups form the simplest class (colored red ).
The fives of all four suits in playing cards